JavaScript中的对象值和对象数组

Question

I am developing a web application in AngularJS. I am confused about references in JavaScript. When do changes on an object affect its references?

For example, I have a controller in my app. and I use that controller to upload files and keep file information in a factory.

   $scope.fileArray = [];
    ...
    ...
    uploadFiles(file){
         $scope.fileArray.push(file);
         ..
         ..
         //on success
         file.params = data["parameters"]; //an array of strings about file path and name
         ...
         ...
    }

In uploadFiles function, I push file object into fileArray. Then when I change or add new attributes to file object, I can see those changes in fileArray.

var fileInfo = {
    infoArray : $scope.fileArray
}

fileFactory.keepFileInfo(fileInfo);

then I keep that array in factory. But this time change on $scope.fileArray is not reflected in factory. What is the logic here?

EDIT

I was wrong. Change in controller object effects factory, too. I wrote this minimal application to see it clearly and in my application I must be making error some where else.

var testApp = angular.module('testApp', []);

testApp.controller('TestController', function($scope, TestFactory) {
    $scope.fileArray = [];

    var files = [];
    files[0] = {
        parameters : {
            name : 'file1.txt',
            path : "user/files"
        }
    }

    $scope.fileArray.push(files[0]);

    files[1] = {
        parameters : {
            name : 'file2.txt',
            path : "user/files"
        }
    }

    $scope.fileArray.push(files[1]);

    files[2] = {
        parameters : {
            name : 'file3.txt',
            path : "user/files"
        }
    }

    $scope.fileArray.push(files[2]);

    TestFactory.setFileArray($scope.fileArray);

    files[0].parameters["name"] = "changed file name";

    console.log($scope.fileArray); //here writes "changed file name"    
    console.log(TestFactory.getFileArray()); //here writes "changed file name", too
});


testApp.factory('TestFactory', function() {
    var factory = {};

    var fileArray = [];

    factory.setFileArray = function(files) {
        fileArray = files;
    }

    factory.getFileArray = function() {
        return fileArray;
    }

    return factory;
});

Answer 1

Let's consider the following example:

var a = {};
var b = {c: a};
console.log(a === b.c);
a.d = {};
console.log(b.c);

If you have an object variable and you assign the member of another object to it, then they have the very same reference, so if you change either one, the other one will be changed as well. The same is the case if you do this with arrays:

var a = {};
var b = [a];
console.log(a === b[0]);
a.d = {};
console.log(b[0]);